1. Field of the Invention
The present invention relates to signal equalization, and more particularly, to a method and apparatus of signal equalization in an optical disc drive system.
2. Description of the Prior Art
In a read channel of a light storage system, a pick-up head of the light storage system reads information from an optical disc to generate a radio-frequency (RF) signal. The RF signal is then processed by a specific low-pass filter and an equalizer. A phase-locked device synchronizes the processed RF signal and the pit/land can be scanned according to the clock of the synchronization signal.
Performance of the read channel relates to jitters between edge timing of the RF data and synchronization signals. The frequency response of the signals read from an optical disc varies from disc to disc. When reading from different disc, the EQ parameters must be adjusted accordingly to obtain the optimum equalizing performance. For variances of the optical discs and the read channel, as well as different requirements for rotational speed, the low-pass filter and the equalizer of the read channel must be adjusted to meet the jitter performance. The conventional adjusting method for the low-pass filter and equalizer is to look up a table for choosing parameters of filters and equalizers according to the types of discs, and utilize a method of trial and error to adjust the parameters to meet the jitter performance.